JP7126957B2 - Aquaculture system and method for producing aquatic products - Google Patents

Description

The present invention relates to a closed circulation aquaculture system for aquaculture.

Conventionally, various facilities and devices have been developed for aquaculture systems for cultivating fish and shellfish and crustaceans in aquaculture tanks constructed on land. a water management device that extracts the aquaculture water from the tank to the outside of the tank, adjusts it to a predetermined condition, and returns it to the tank; an aeration channel that aerates the treated water supplied from the water management device; There have been reports of aquaculture facilities equipped with an airflow device that produces a

On the other hand, a land-based aquaculture system that introduces biofloc technology has been attracting attention, and has been demonstrated mainly in shrimp aquaculture in Southeast Asia, etc., and is also being introduced in Japan (for example, Non-Patent Document 1).

Registered Utility Model No. 3022030

Hokusui Experimental Report 86, 81-102 (2014)

An object of the present invention is to provide an aquaculture system in which the quality (C/N ratio) of aquaculture water can be easily controlled in a closed circulation aquaculture system incorporating biofloc technology.

As a result of earnest research to solve the above problems, the inventors of the present invention have found that the following inventions meet the above objects, and have completed the present invention.

That is, the present invention relates to the invention of the following aquaculture system.
<1> An aquaculture system using a biofloc, comprising a nitrifying bacterium-immobilizing material in which a nitrifying bacterium is supported on a carrier in an aquaculture tank.
<2> The aquaculture system according to <1>, wherein the carrier in the nitrifying bacteria-immobilizing material is a foam carrier.
<3> The culture tank is provided with an air injector for circulating the water flow in the culture tank and an aerator for discharging the culture water and mixing air, wherein the nitrifying bacteria immobilizing material is The aquaculture system according to <1> or <2>, packed in a container having water.
<4> The aquaculture system according to <3>, wherein a water-permeable container filled with the nitrifying bacteria-immobilizing material is arranged downstream of the air injector and/or the aerator.
<5> The aquaculture system according to any one of <1> to <4>, wherein the aquaculture tank is provided with at least one of a water wheel, a feeder, and a heat insulator.
<6> The aquaculture system according to any one of <1> to <5>, wherein the aquaculture tank is installed on land.

Another aspect of the present invention is an invention relating to the following method for producing aquatic products.
<7> A method for producing an aquatic product, comprising cultivating a target aquatic product using the aquaculture system according to any one of <1> to <6>.
<8> The method for producing aquatic products according to any one of <1> to <7>, wherein the aquatic products grown in the aquaculture tank are marine products.
<9> The method for producing marine products according to <8>, wherein the marine products are crustaceans.
<10> The method for producing an aquatic product according to <9>, wherein the crustacean is an order of the order Prawn.
<11> The method for producing an aquatic product according to <10> above, wherein the shrimp is of the superfamily Kuruma shrimp.
<12> The method for producing an aquatic product according to <11> above, wherein the above-mentioned Kuruma shrimp superfamily is Kuruma shrimp family.
<13> The method for producing an aquatic product according to <12>, wherein the Kuruma shrimp belongs to the genus Litopenius.
<14> The method for producing an aquatic product according to <13>, wherein the Litopenius genus is Litopenaeus vannamei.

Another aspect of the present invention is the following invention.
<X1> A nitrifying bacteria-immobilizing material in which nitrifying bacteria are supported on a carrier.
<X2> The nitrifying bacteria-immobilizing material according to <X1> above, for use with bioflocs for aquaculture.
<X3> The nitrifying bacteria-immobilizing material according to <X1> or <X2>, wherein the carrier is a foamed carrier.

According to the present invention, it is possible to efficiently cultivate aquatic organisms by appropriately maintaining the water quality of a culture tank in a biofloc culture system.

1 is a plan view showing an aquaculture tank constituting an aquaculture system according to an embodiment of the present invention; FIG. BRIEF DESCRIPTION OF THE DRAWINGS It is partially-omission sectional drawing of the culture system which is embodiment of this invention. FIG. 2 is an enlarged view with partial omission of the culture tank shown in FIG. 1;

Hereinafter, the present invention will be described in detail with reference to examples, etc., but the present invention is not limited to the following examples, etc., and can be arbitrarily modified without departing from the scope of the present invention. In this specification, "A to B" or "A to B" are used as expressions including numerical values or physical quantities before and after them. Also, in this specification, the expression "A and/or B" means "either or both of A and B." That is, "A and/or B" includes "only A," "only B," and "both A and B."

The aquaculture system of the present invention (hereinafter simply referred to as the "aquaculture system of the present invention") is an aquaculture system using bioflocs, and includes a nitrifying bacteria-immobilizing material in which nitrifying bacteria are supported on a carrier in a culture tank. , the aquaculture system. The aquaculture system of the present invention is preferably a closed circulation aquaculture system.

The culturing system of the present invention is premised on being a culturing system using bio-flocks. In the present invention, the term "bio-floc" refers to a mass of microorganisms artificially formed in the water of aquaculture tanks for aquatic products such as fish and shellfish and crustaceans. This biofloc reduces toxic ammonia and nitrous acid that increase due to feeding, and the biofloc itself can also be used as a protein source.
As used herein, the term "culture water" refers to water or an aqueous solution used for breeding aquatic organisms in an aquarium, and includes fresh water, sea water, and brackish water. These are selected appropriately for each aquatic organism to be reared. Seawater and brackish water may be prepared using artificial seawater. Appropriate changes may be made depending on the breeding season from egg to shipping size.

One of the characteristics of the aquaculture system of the present invention is that, in the culture tank, the nitrifying bacteria contained in the biofloc and a carrier holding the nitrifying bacteria (nitrifying bacteria-immobilizing material) are used together as the nitrifying bacteria. By doing so, ammonia nitrogen is synergistically nitrified not only by the nitrifying bacteria contained in the biofloc but also by the nitrifying bacteria retained in the carrier, so that the growth of the nitrifying bacteria causes the biofloc to become excessive. increase is suppressed.

Examples of nitrifying bacteria include ammonia-oxidizing bacteria and nitrite-oxidizing bacteria. "Ammonia-oxidizing bacteria" are bacteria that oxidize ammonium nitrogen, such as ammonium ions, in culture water under an aerobic atmosphere to convert them into nitrite ions. It is a bacterium that further oxidizes the nitrite ions in the culture water produced by P. to nitrate ions under an aerobic atmosphere.

In the present invention, the types of nitrifying bacteria include, but are not limited to, Nitrobacter, Nitrospina, Nitrococcus, and the like. , aquaculture density, size of aquaculture tank (amount of aquaculture water), temperature, and other conditions. Also, the nitrifying bacteria contained in the biofloc and the nitrifying bacteria immobilized on the carrier may be the same or different.

The nitrifying bacterium-immobilizing material is a material in which nitrifying bacteria are held on a carrier.
The type of carrier is not particularly limited as long as it does not interfere with the carrying of nitrifying bacteria and does not adversely affect the culture target, and may be inorganic carriers made of inorganic substances such as ceramics, or organic carriers made of organic substances such as resins. Available.

The shape of the carrier is not limited as long as it does not interfere with the carrying of the nitrifying bacteria, and examples thereof include powder, granules, lumps, plates, and the like. Porous carriers are preferred because they can support more nitrifying bacteria and have better contact with culture water.

As inorganic porous carriers, for example, natural mineral silicate compounds such as montmorillonite, zeolite, and kaolin are suitable for supporting nitrifying bacteria, and are expected to improve colonization of nitrifying bacteria. Inorganic carriers other than silicate compounds such as alumina can also be used. These may be used alone or in combination of two or more.

The particle size of the inorganic carrier is not particularly limited as long as the carrying of nitrifying bacteria is not inhibited. On the other hand, too small particles may be sieved and removed for the purpose of uniforming quality.
As the granular carrier, for example, one having a particle size of about 0.1 μm to 250 μm can be used, but it is not limited to this.

The organic porous carrier is not limited as long as it is a structure made of a polymer that does not dissolve in water and has a high affinity for microorganisms. material. Specific examples of organic porous carriers that can be used include foam carriers, nonwoven carriers, porous gel carriers, hollow fiber membrane carriers, and the like. These may be used alone or in combination of two or more.
In particular, the foamable carrier is a structure having interconnected cells, has a large specific surface area, and can immobilize nitrifying bacteria at a high concentration per unit volume. . Examples of commercially available foam carriers include Microbreath (registered trademark) (manufactured by Aion Co., Ltd.), Biotube (registered trademark) (manufactured by JFE Engineering Corporation), APG (manufactured by Nisshinbo Chemical Co., Ltd.), and porous cellulose. Carrier (manufactured by EYELA), Biofrontier Net (manufactured by Kansai Kako), Aqua Cube (manufactured by Sekisui Aqua System Co., Ltd.) and the like. The size is arbitrary, but when used in a water-permeable container to be described later, a size larger than the holes (mesh) of the water-permeable container is selected so as not to flow out.

Any method may be used to immobilize the nitrifying bacteria on the carrier. For example, a dispersion of nitrifying bacteria dispersed in water may be mixed with the carrier. After mixing, the nitrifying bacteria are immobilized while proliferating on the carrier by, for example, contacting with oxygen to obtain a nitrifying bacteria-immobilized material.

The nitrifying bacteria-immobilizing material may be placed in contact with the culture water in the culture tank. In principle, they may be dispersed in the water of the culture tank (aquaculture water), but when they are dispersed, it becomes difficult to collect them. Therefore, a mode of putting the nitrifying bacteria-immobilizing material in a water-permeable container is a preferred mode of use. As a water-permeable container, specifically, a water-permeable basket-like container is exemplified.
Here, the “basket-shaped container” is a substantially rectangular parallelepiped housing with each surface of the container formed in a net shape (or a hole shape) or the like so that water can pass through. It can be filled with a bacteria-immobilizing material.
The shape and size of the water-permeable container are appropriately selected in consideration of the type and size of the nitrifying bacteria-immobilizing material, the size of the aquaculture facility, the type and growth rate of the marine product to be cultivated, and the like. Also. The material may be either metal or plastic, and may be appropriately selected according to the conditions of aquaculture facilities.
In aquaculture tanks, by using the nitrifying bacteria-immobilizing material in a water-permeable container (for example, a basket-like container), the collection and arrangement of the nitrifying bacteria-immobilizing material are facilitated, and the state of the culture water (C /N ratio), it becomes easy to control the amount of the nitrifying bacteria-immobilizing material (that is, the amount of nitrifying bacteria other than bioflocs). In addition, since the nitrifying bacteria-immobilizing material is placed in a water-permeable container, it can be stably used without flowing away and disappearing.

If the aquaculture tank is equipped with an air injector for circulating the water flow in the aquaculture tank and an aerator for discharging the aquaculture water and mixing air, it is placed in a water-permeable container. The nitrifying bacteria-immobilizing material is preferably arranged downstream of the air injector and/or the aerator in the aquaculture system of the present invention. The term downstream is used herein to mean downstream of the water flow generated by the air injector and/or the aerator.
In addition, when the ability of nitrifying bacteria (nitrification) is excessive, it is possible to easily adjust the nitrification by adjusting the number of containers with water permeability and the amount of nitrifying bacteria-fixing material in each container. is. In addition, since the nitrifying bacteria-immobilizing material can be easily replaced, it is useful when the ability of the material has decreased or when bacteria have propagated and need to be replaced.
In the present invention, the air injector and the aeration device eject water and air, respectively. ” aims to discharge culture water and mix air, and the outlet is above the water. Specific examples are as described in the embodiments of the present invention to be described later.

By placing the nitrifying bacteria-immobilizing material in a water-permeable container downstream of an air injector or an aerator that generates a water flow, the nitrifying bacteria-immobilizing material is mixed with water in a so-called fluidized bed state. Since the contact is forced, the nitrifying bacteria retained in the nitrifying bacteria-immobilizing material can be utilized to the maximum.
Furthermore, even if the amount of the nitrifying bacteria-fixing material is the same, the nitrifying action of the nitrifying bacteria can be controlled by adjusting the amount of water in the air injector or the aerator, making it easier to control the water quality (C/N ratio) of the culture water. becomes possible.

Moreover, it is preferable that the aquaculture tank is provided with at least one of a water wheel, a feeder, and a heat insulating material. Specific examples are as described in the embodiments of the present invention to be described later.

A preferred embodiment of the aquaculture system of the present invention is a so-called land-based aquaculture system in which aquaculture tanks are installed on land.

In the aquaculture system of the present invention, aquatic products to be cultivated include marine products. Marine products include crustaceans. Crustaceans include shrimps (particularly the order Eburiformes). "Shrimp" is not limited in size, and classified as food includes so-called lobster, prawn, and shrimp.

In academic classification, the shrimp to be the subject of the present invention is preferably of the order Eburiformes, and within the order of the Eburiformes, the superfamily Pteridae is preferred. Among the Kurumaebi superfamily, Kuruma shrimp family is preferable. Organisms of the Penaeidae family, for example, shrimp belonging to the genus Farfantepenaeus, Fenneropenaeus, Litopenaeus, Marsupenaeus, Melicertus, Metapenaeopsis, Metapenaeus, Penaeus, Trachypenaeus, and Xiphopenaeus.

Among the Kuruma shrimp family, for example, edible shrimp include Marsupenaeus japonicus, Melicertus canaliculatus, Black tiger shrimp (Penaeus monodon), Penaeus chinensis, Penaeus semisulcatus, Penaeus latisulcatus), Indian shrimp (Fenneropenaeus indicus), Yoshi shrimp (Metapenaeus ensis), Tosa shrimp (Metapenaeus intermedius), Penaeus occidentalis, Blue shrimp (Penaeus stylirostris), Red tail shrimp (Penaeus pencicillatus), Vannamei shrimp (Litopenaeus vannamei), etc. It is not limited to these.

Litopenaeus genus Litopenius, in particular Litopenaeus vannamei, is one of the objects to be cultured in the culture system of the present invention.

In addition, shrimp includes species that have swimming ability and species that do not have swimming ability. Floating species are more suitable for production in overcrowded conditions because they can use tanks three-dimensionally. In the aquaculture system of the present invention, both species of shrimp can be cultivated, but shrimp species with swimming ability are more preferable because overcrowded conditions increase the chances of contact between shrimps and increase productivity. Swimming species include Marsupenaeus japonicus, Penaeus monodon, Pandalus nipponensis, Pandalopsis coccinata, Lucensosergia lucens, Pandalus eous, and Penaeus chinensis. , Metapenaeus ensis, and Litopenaeus vannamei.
In addition, non-sand-sinking shrimp, which rarely burrow into sand, are preferred in the present invention because they can be reared at a particularly high density in the aquaculture system of the present invention. Examples of non-sinking shrimp include Litopenaeus vannamei and Korai shrimp.

The method for producing an aquatic product of the present invention is a method of cultivating a target aquatic product using the aquaculture system of the present invention.
According to the method for producing aquatic products of the present invention, it is possible to easily control the quality of aquaculture water in a closed-circulation aquaculture system incorporating biofloc technology, and to efficiently cultivate target aquatic products. becomes possible. In efficient aquaculture, survival rate can be increased in one aspect. In one aspect, feed efficiency can be increased. Moreover, in one aspect, the growth can be accelerated and the cultivation period can be shortened.

Since the aquatic products to be cultivated are as described above, the description is omitted. When the object of the aquatic product production method is shrimp, the object of aquaculture includes juvenile shrimp to parent shrimp.
The term "juvenile shrimp" as used in the present invention means shrimp weighing less than 1 g, and does not include shrimp that have grown from eggs to juvenile shrimp. In addition, "parent shrimp" means a shrimp that has grown from the juvenile shrimp. Parent shrimp, for example, vannamei shrimp, is usually shipped after being grown to about 15 g or more.

Check the water quality regularly and adjust it so that it falls within the appropriate range. The water quality is controlled by the type and amount of the nitrifying bacteria-immobilizing material used together with the bio-floc. They are reared at a pH of 5-10, preferably 6-9, more preferably 7-8. When the pH drops or rises, it may be adjusted by adding an alkaline agent or an acid in addition to the nitrifying bacteria-immobilizing material, or by adjusting the water exchange rate. The water temperature is maintained at 23-32°C, preferably 25-30°C, more preferably 27-29°C. The water temperature can be adjusted by heating with sunlight, a heater, or the like, or by cooling with a cooler, ice, or the like.

Hereinafter, as an embodiment of the present invention, an example of the closed circulation type aquaculture system of the present invention will be specifically described with reference to the drawings, but the present invention is not limited to this. In addition, in all the drawings, the same constituent elements are denoted by the same reference numerals, and the description thereof will be omitted as appropriate.

An aquaculture system 100 that is an embodiment of the present invention will be described based on FIGS. 1 to 3. FIG.
The aquaculture system 100 is a land-based aquaculture system and is suitable for aquaculture of vannamei shrimp, but the aquaculture target is not limited to this, and can be the aquatic product described above.

As shown in FIG. 1 , the aquaculture system 100 of this embodiment has three aquaculture tanks 50 . The aquaculture tank 50 is formed inside the thermal insulation house 10 as shown in FIG.

In this embodiment, three aquaculture tanks 50 are formed on the ground G covered with the heat insulating house shown in FIG. As used herein, the term "thermal insulation house" refers to a structure for maintaining the temperature of aquaculture aquarium facilities within a predetermined range. When the temperature outside the heat-insulating house is lower than the temperature suitable for aquaculture, the temperature inside the heat-insulating house can be kept at a temperature suitable for aquaculture by isolating the heat-insulating house from the outside air.
As shown in FIG. 2, the thermal insulation house 10 is constructed by covering a kamaboko-shaped building 11 formed by combining a plurality of pipe materials, angle materials, etc. with a synthetic resin film material 12 . Although omitted in FIG. 2, in the present embodiment, the heat insulating house 10 has a three-span structure. Since the size and number of connected houses of the heat insulating house 10 are not limited, they can be set according to the size and conditions of the construction site.

In this embodiment, as shown in FIG. 2, the upper surface and the outer peripheral surface of the culture tank 50 are covered with a plurality of plate-shaped heat insulating materials 40 (for example, foamed synthetic resin material). Above the culture tank 50 , a plurality of heat insulating materials 40 are detachably arranged on a plurality of support beams 41 horizontally supported by structural members of the building 11 . The heat insulating material 40 has a heat insulating function and also has a function of shielding light (sunlight) from the outside.
When cultivating Vannamei shrimp in the culture tank 50, the temperature of the culture water W must be kept relatively high (approximately 28° C.). Since the whole aquaculture tank 50 is covered with the heat insulating material 40 and arranged in the heat-insulating house 10, dissipation of the aquaculture water W can be suppressed. In addition, since the heat insulating material 40 suppresses changes in the water temperature of the culture water W in the culture tank 50, utility costs can be reduced.

Further, as shown in FIG. 1 , a boiler 30 that is means for heating the culture water W in the culture tank 50 and a fuel tank 31 that stores the fuel used in the boiler 30 is arranged near the boiler 30 . Thereby, the temperature in the heat insulating house 10 can be raised.
In the aquaculture system 100, the boiler 30 is operated as necessary, and the air injector 60, the water wheel 70, the aerator 80, By operating the circulation pump 91 and the automatic feeder 20, it is possible to cultivate aquatic products (eg, vannamei shrimp) in the culture water W in the culture tank 50. FIG.

As shown in FIGS. 2 and 3, the culture tank 50 has a rectangular shape in plan view. slopes downward toward the inside of the aquaculture tank 50 (see FIG. 2).

In the aquaculture system 100 of the present embodiment, the aquaculture tank 50 forms a recessed portion from the ground G in the direction of gravity, and the inner wall surface and the bottom surface of the recessed portion are provided with waterproof synthetic resin sheets. formed.
The bottom surface 53 of the culture tank 50 has a rectangular shape in plan view and is generally horizontal.

In the present embodiment, the aquaculture system 100 is provided with the aquaculture tank 50 by laying a synthetic resin sheet material (for example, a PE protective sheet) in the concave portion formed in the ground G, but instead of the aquaculture tank 50 Concrete, plastic, and metal aquaculture tanks can also be used.

As shown in FIG. 2, the inner wall surfaces 51 and 52 of the culture tank 50 are formed so as to form a downward slope toward the inside of the culture tank 50, so that the inner wall surfaces 51 and 52 form an obtuse angle with respect to the bottom surface 53. Therefore, it is easy to collect the shrimp and the residue when harvesting. The inclination angle of the inner wall surfaces 51 and 52 of the culture tank 50 is set to about 45 degrees with respect to the horizontal plane H, but it is not limited to this. A high angle of about 70 degrees is also possible.

As shown in FIGS. 1 to 3, in the aquaculture tank 50, a horizontal end portion 54a is located in a region further inside the aquaculture tank 50 than the four inner wall surfaces 51, 51, 52, 52. By erecting the partition wall 54 , an endless flow channel 55 is formed in which the water flow S of the culture water W can circulate in the horizontal direction around the partition wall 54 .

A plurality of air injectors 60 are arranged along the longitudinal direction of the endless water channel 55 on the bottom surface 53 of the aquaculture tank 50 . A pair of water wheels 70 , 70 are arranged with a partition wall 54 interposed therebetween in a portion near the end in the longitudinal direction of the culture tank 50 .
In addition, aeration devices 80 are arranged near the longitudinal ends of the aquaculture tanks 50, respectively. Furthermore, a sedimentation tank 90 and a circulation pump 91 are arranged outside the short side portion of the aquaculture tank 50, respectively. An automatic feeder 20 and a circulation pump 91 are arranged outside one short side of the culture tank 50 .

Further, as shown in FIGS. 1 and 3 , the water turbine 70 includes rotating blades 71 rotatable about a horizontal axis and a motor 72 for driving the rotating blades 71 . The direction of rotation of the rotary vane 71 can be switched.

As shown in FIGS. 1 and 3, by ejecting air-mixed water from a plurality of air injectors 60 provided on the bottom surface 53 of the culture tank 50, the culture water W in the culture tank 50 is injected with Since a circulating water flow S that continuously swirls around the partition wall 54 as indicated by the arrow can be generated, aquatic organisms that have the property of swimming along the water flow S (for example, prawns, prawns, botan prawns, grape prawns, etc.) can be generated. , long-nosed shrimp, sakura shrimp, northern red shrimp, blue-spotted shrimp, yellow shrimp, vannamei shrimp).

In the aquaculture tank 50, oxygen in the air can be efficiently supplied to the aquaculture water W by operating the aerator 80 and the plurality of water turbines . Since the rotation direction of the rotating blades 71 of the water wheel 70 can be changed, the rotating blades 71 can be rotated in an appropriate direction according to conditions such as the direction of the circulating water flow S. When the rotating blades 71 of the water wheel 70 are rotated forward, the speed of the water flow S does not increase, but when they are rotated in the reverse direction against the water flow S, the water is pushed out and the flow becomes faster. This is useful when the water flow S at the air injector is insufficient.

Downstream of the outlet port (not shown) of the aeration device 80, a water-permeable basket-like container (not shown) containing a large number of particulate nitrifying bacteria-immobilizing materials is arranged. In the nitrifying bacteria-immobilizing material of the present embodiment, the nitrifying bacteria can be immobilized at a high concentration, and the water-swellable polyurethane foam (when expanded: 10 × 10 x 10 mm) is used. However, other carriers can also be used. For example, a highly durable inorganic porous carrier may be used.
The aeration device 80 discharges culture water and mixes with air, thereby activating nitrifying bacteria, which are aerobic bacteria. Furthermore, since the nitrifying bacteria immobilizing material placed in the basket-shaped container flows and is forced into contact with water in the container, the nitrifying bacteria retained in the nitrifying bacteria immobilizing material can be utilized to the maximum. can. Since the nitrification action by the nitrifying bacteria can be controlled also by the amount of water in the aerator, it is possible to more easily control the water quality (C/N ratio) of the culture water.

In the present embodiment, the nitrifying bacteria-immobilizing material placed in a water-permeable basket-shaped container is arranged downstream of the aeration device 80. Among the plurality of air injectors 60, one or more air injectors At 60, a nitrifying bacteria-immobilizing material contained in a water-permeable basket-like container may be placed.

Although the embodiment of the present invention has been described above, it should be considered that the embodiment disclosed this time is illustrative in all respects and is not restrictive. In particular, matters not explicitly disclosed in the embodiments disclosed this time, such as operating conditions, operating conditions, various parameters, dimensions of components, weights, volumes, etc. Instead, a value that can be easily assumed by a person skilled in the art is adopted.

INDUSTRIAL APPLICABILITY The present invention can be widely used in fields such as the aquaculture industry and the aquaculture industry as a closed circulation aquaculture system for growing aquatic products such as shrimp on land. For example, in one embodiment, not only the nitrifying bacteria contained in the biofloc but also the nitrifying bacteria supported on the carrier assist the nitrification of ammonium nitrogen, thereby avoiding an excessive amount of biofloc. Thus, the quality of culture water can be maintained. In another aspect, the quality of the culture water can be maintained by controlling the C/N ratio in the culture water. According to the present invention, it is possible to produce more delicious, fresh and/or long-lasting aquatic products.

REFERENCE SIGNS LIST 10 thermal insulation house 10c top 11 building 12 synthetic resin film material 16 ventilation port 20 automatic feeder 30 boiler 31 fuel tank 40 heat insulating material 41 support beam 50 culture tank 51, 52 inner wall surface 53 bottom surface 54 partition wall 54a end portion 55 endless running water channel 60 Air injector 70 Water wheel 71 Rotating blade 72 Motor 80 Aerator 90 Sedimentation tank 91 Circulation pump 100 Aquaculture system G Ground H Horizontal surface S Water flow

Claims (12)

An aquaculture system using a bio-flock, comprising a culture tank comprising a nitrifying bacteria immobilizing material in which nitrifying bacteria are supported on a carrier ; an air injector for circulating water flow in the culture tank; and an aerator for mixing the
The nitrifying bacteria-immobilizing material is packed in a water-permeable container,
An aquaculture system , wherein a water-permeable container filled with the nitrifying bacteria-immobilizing material is arranged downstream of the air injector and/or the aerator . 2. The aquaculture system according to claim 1, wherein the carrier in said nitrifying bacteria-immobilizing material is a foam carrier. 3. The aquaculture system according to claim 1, wherein the aquaculture tank is provided with at least one of a water wheel, a feeder, and a heat insulating material. 4. The aquaculture system according to any one of claims 1 to 3 , wherein the aquaculture tank is installed on land. A method for producing aquatic products, comprising cultivating target aquatic products using the aquaculture system according to any one of claims 1 to 4 . 6. The method for producing aquatic products according to claim 5 , wherein the aquatic products are marine products. 7. The method for producing marine products according to claim 6 , wherein the marine products are crustaceans. 8. The method for producing aquatic products according to claim 7 , wherein the crustacean is of the order Eurasian. 9. The method for producing aquatic products according to claim 8 , wherein the Ebina is a Kurumae superfamily. 10. The method for producing aquatic products according to claim 9 , wherein said Kuruma shrimp superfamily is Kuruma shrimp family. 11. The method for producing aquatic products according to claim 10 , wherein the Kuruma shrimp belongs to the genus Litopenius. 12. The method for producing aquatic products according to claim 11 , wherein the Litopenius genus is Litopenaeus vannamei.

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